Rifaximin derivative and uses thereof

ABSTRACT

25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof is provided. Methods of treatment of bowl related disorders using isolated and/or purified 25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof are also provided.

RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/707,858, filed May 8, 2015, which is a continuation of U.S.application Ser. No. 14/319,060, filed Jun. 30, 2014, which is acontinuation of International Application No. PCT/US2013/023110, filedJan. 25, 2013, which claims the benefit of U.S. Provisional ApplicationNo. 61/590,516, filed Jan. 25, 2012, the entire contents of which areexpressly incorporated herein by reference.

BACKGROUND

The number of species and strains of bacteria resistant to antibioticsand the number of antibiotics to which they are resistant has increasedworld-wide. As a result, infections that had been readily treatable byantibiotics may no longer be so. Increased resistance of bacterialinfections to antibiotic treatment has now become a generally recognizedmedical problem.

Throughout the developed world there is public and governmental concernabout the increasing prevalence of antimicrobial resistance toantibiotic therapy in bacteria that cause diseases in humans. Manypathogens exist for which there are few effective treatments, and thenumber of strains resistant to available drugs is continuallyincreasing. New antimicrobial agents and improved methods are thusneeded for the treatment and prevention of infections by such pathogens.

SUMMARY

Provided herein is a 25-desacetyl rifaximin and methods of using thesame for the treatment of at least one bowel related disorder. Bowelrelated disorders, include, for example, irritable bowel syndrome,travelers' diarrhea, small intestinal bacterial overgrowth, Crohn'sdisease, chronic pancreatitis, pancreatic insufficiency, hepaticencephalopathy, pouchitis, enteritis and colitis (including, ulcerativecolitis) and other related conditions. In certain embodiments, the25-desacetyl rifaximin is isolated and/or purified.

Embodiments relate to a purified and/or isolated 25-desacetyl rifaximinor a pharmaceutically acceptable salt thereof.

Embodiments also relate to a purified and/or isolated 25-desacetylrifaximin having the formula:

Embodiments are directed to pharmaceutical compositions comprising25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, 25-desacetyl rifaximin is 50%-99.9% pure orpurified.

In some embodiments, 25-desacetyl rifaximin is 90% pure or purified.

In some embodiments, 25-desacetyl rifaximin is 95% pure or purified.

In some embodiments, 25-desacetyl rifaximin is from between about 50% toabout 99.9% pure or purified.

In some embodiments, a 25-desacetyl rifaximin composition is formulatedas one or more of a tablet, caplet, capsule, or liquid dosage form.

Embodiments are directed to methods for treating or preventing one ormore bowel related disorders, comprising administering to a subject inneed thereof a therapeutically effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, the one or more bowel related disorders compriseirritable bowel syndrome, travelers' diarrhea, small intestinalbacterial overgrowth, Crohn's disease, pancreatitis, pancreaticinsufficiency, peritonitis, hepatic encephalopathy, pouchitis,infectious diarrhea, inflammatory bowel disease, diverticular disease,Clostridium, C. difficile disease, H. pylori infection, enteritis,colitis, ulcerative colitis, and bacterial periodontal conditions.

In some embodiments, the traveler's diarrhea is caused by exposure toone or more enteric pathogens.

In some embodiments, the one or more enteric pathogens compriseSalmonella spp., Shigella spp., Campylobacter spp., Aeromonas,Plesiomonas, Vibro spp., Yersinia entercolitica, E. coli,Enterotoxigenic Escherichia coli (ETEC), E. coli 0157:H7, C. difficileor H. pylori.

In some embodiments, the enteric pathogens comprise one or more of agram-positive bacteria, a gram-negative bacteria, an aerobic bacteria oran anaerobic bacteria.

In some embodiments, E. coli comprises enterotoxigenic and/orenteroaggregative strains.

In some embodiments, the methods further comprise administeringrehydration therapy (RT) to the subject.

In some embodiments, the RT is administered before, during and/or afterthe administration of the 25-desacetyl rifaximin.

In some embodiments, the RT comprises one or more of oral rehydrationtherapy or intravenous rehydration therapy.

Embodiments relate to methods for alleviating the symptoms of bloating,abdominal pain, gas or flatulence in a subject comprising administeringto a subject in need thereof a therapeutically effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof.

Embodiments are also directed to methods of treating disorders caused byabnormal GI flora comprising administering to a subject in need thereofa therapeutically effective amount of 25-desacetyl rifaximin or apharmaceutically acceptable salt thereof.

In some embodiments, the abnormal GI flora comprises one or more ofenteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC),Shigella spp., Salmonella spp., Campylobacter spp., Vibrio, H. pylori,Staphylococcus spp., and C. difficile.

Embodiments are directed to kits comprising 25-desacetyl rifaximin andinstructions for use.

Embodiments are also directed to methods for treating or preventingtraveler's diarrhea in a subject comprising administering to a subjectin need thereof a therapeutically effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt thereof. In particularaspects, the traveler's diarrhea to be treated is caused by exposure toE. coli.

Embodiments relate to methods for treating or preventing hepaticencephalopathy in a subject comprising administering to a subject inneed thereof a therapeutically effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt thereof.

Embodiments also relate to methods for alleviating the symptoms ofbloating, gas or flatulence in a subject comprising administering to asubject in need thereof a therapeutically effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof.

Embodiments are directed to methods for treating irritable bowelsyndrome in a subject comprising administering to a subject in needthereof a therapeutically effective amount of 25-desacetyl rifaximin ora pharmaceutically acceptable salt thereof.

In some embodiments, the 25-desacetyl rifaximin or pharmaceuticallyacceptable salt thereof is administered orally. In some embodiments, the25-desacetyl rifaximin or pharmaceutically acceptable salt thereof isadministered topically. In some embodiments, the topically administered25-desacetyl rifaximin or pharmaceutically acceptable salt thereof isadministered in a cream, enema, ointment, lotion, or gel.

Embodiments are also directed to the use of 25-desacetyl rifaximin as ametabolite of rifaximin. In some embodiments, rifaximin is administeredto a subject in need of treatment for a bacterial infection in an amountthat results in a therapeutically effective amount of 25-desacetylrifaximin in the subject.

Embodiments relate to methods for treating a bowel related disorder byadministering a metabolite of rifaximin to a subject in need oftreatment therefore.

Embodiments are also related to methods of inhibiting bombesin BB1comprises administering 25-desacetyl rifaximin.

Embodiments also relate to methods of inhibiting N-formyl peptidereceptor FPR1 comprises administering 25-desacetyl rifaximin.

Embodiments are directed to methods for treating or preventing one ormore skin or mucous membrane infections, comprising administering to asubject in need thereof a therapeutically effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, one or more skin or mucous membrane infectionscomprise vaginal infections, ear infections, lung infections,periodontal conditions, rosacea, and other infections of the skin and/orother related conditions.

Embodiments are also directed to a method for making 25-desacetylrifaximin by reacting rifaximin with methanol (MeOH) and sodiumhydroxide (NaOH). In one aspect the NaOH is 2N NaOH.

DETAILED DESCRIPTION

Provided herein is a rifaximin derivative 25-desacetyl rifaximin havingthe formula:

The 25-desacetyl rifaximin provided herein is a rifaximin derivative andbiological metabolite. Rifaximin (INN; see The Merck Index, XIII Ed.,8304) is an antibiotic pertaining to the rifamycin class, specificallyit is a pyrido-imidazo rifamycin which is described and claimed in theItalian Patent IT 1154655. European Patent EP 0161534 describes andclaims a process for its production starting from rifamycin O (The MerckIndex, XIII Ed., 8301). Rifaximin is currently used in the treatment oftraveler's diarrhea and hepatic encephalopathy.

Also provided are pharmaceutically acceptable salts, which include thosein which 25-desacetyl rifaximin functions as an acid and is reacted withan appropriate base to form, e.g., sodium, potassium, calcium,magnesium, ammonium, and chorine salts. Those skilled in the art willfurther recognize that acid addition salts of the claimed compounds canbe prepared by reaction of 25-desacetyl rifaximin the appropriateinorganic or organic acid via any of a number of known methods.Alternatively, alkali and alkaline earth metal salts of acidic25-desacetyl rifaximin are prepared by reacting the 25-desacetylrifaximin with the appropriate base via a variety of known methods.

Representative salts of 25-desacetyl rifaximin include, for example,nontoxic salts and the quaternary ammonium salts which are formed, forexample, from inorganic or organic acids or bases by means well known inthe art. Pharmaceutically acceptable acid addition salts of the25-desacetyl rifaximin include, for example, salts derived from nontoxicinorganic acids such as hydrochloric, nitric, phosphoric, sulfuric,hydrobromic, hydriodic, hydrofluoric, phosphorous, and the like, as wellas the salts derived from nontoxic organic acids, such as aliphaticmono- and dicarboxylic acids, phenyl-substituted alkanoic acids, hydroxyalkanoic acids, alkanedioic acids, aromatic acids, aliphatic andaromatic sulfonic acids, etc. Such salts can include sulfate,pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate,monohydrogenphosphate, dihydrogenphosphate, metaphosphate,pyrophosphate, acetate, trifluoroacetate, propionate, caprylate,isobutyrate, oxalate, malonate, succinates suberate, sebacate, fumarate,maleate, mandelate, benzoate, chlorobenzoate, methylbenzoate,dinitrobenzoate, phthalate, benzensoulfonate, toluenesulfonate,phenylacetate, citrate, lactate, maleate, tartrate, methanesulfonate,and the like. Also contemplated are salts of amino acids such asarginate and the like and gluconate, galacturonate (see, for example,Berge S. M. et al., “Pharmaceutical Salts,” Journal of PharmaceuticalScience, 1977; 66:1-19). The acid addition salt of 25-desacetylrifaximin can be prepared by contacting the free base form with asufficient amount of the desired acid to produce the salt.

Pharmaceutically acceptable base addition salts are formed with metalsor amines, such as alkali and alkaline earth metals or organic aminesExamples of metals used as cations are sodium, potassium, magnesium,calcium, and the like. Examples of suitable amines areN,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine,dicyclohexylamine, ethylenediamine, N-methylglucamine, and procaine(see, for example, Berge S. M., supra., 1977). The base addition saltsof the acidic compounds are prepared by contacting the free acid formwith a sufficient amount of the desired base to produce the salt.Additionally, basic nitrogen containing groups can be quaternized withsuch agents as lower alkyl halides such as methyl, ethyl, propyl, andbutyl chlorides, bromides and iodides; dialkyl sulfates like dimethyl,diethyl, and dibutyl sulfate; and diamyl sulfates, long chain halidessuch as decyl, lauryl, myristyl and stearyl chlorides, bromides andiodides, aralkyl halides like benzyl and phenethyl bromides and others.

A solvate includes, for example, a complex of a solvent and 25-desacetylrifaximin in the solid state. Exemplary solvates would include, forexample, complexes of a compound with ethanol or methanol.

The term “subject” refers to animals such as mammals, including, forexample, primates (e.g., humans), cows, sheep, goats, horses, dogs,cats, rabbits, rats, mice and the like. In certain embodiments, thesubject is a human.

It is also to be understood that the terminology used herein is forpurposes of describing particular embodiments only, and is not intendedto be limiting. As used in the specification and the appended claims,the singular forms “a”, “an”, and “the” include plural referents unlessthe context clearly indicates otherwise.

Unless otherwise defined, all technical and scientific terms used hereinhave the same meaning as commonly understood by one of ordinary skill inthe art. All publications, patent applications, patents, and otherreferences mentioned herein are incorporated by reference.

Treatment of Skin or Mucous Membrane Infections

Described herein are methods of using 25-desacetyl rifaximin to treatvaginal infections, ear infections, lung infections, periodontalconditions, rosacea, and other infections of the skin and/or otherrelated conditions.

Provided herein are vaginal pharmaceutical compositions to treat vaginalinfection, particularly bacterial vaginosis, to be administeredtopically, including vaginal foams and creams, containing atherapeutically effective amount of 25-desacetyl rifaximin, preferablybetween about 50 mg and 2500 mg.

Pharmaceutical compositions known to those of skill in the art for thetreatment of vaginal pathological conditions by the topical route can beadvantageously used with 25-desacetyl rifaximin. For example, vaginalfoams, ointments, creams, gels, ovules, capsules, tablets andeffervescent tablets can be effectively used as pharmaceuticalcompositions containing 25-desacetyl rifaximin, which can beadministered topically for the treatment of vaginal infections,including bacterial vaginosis.

Also provided herein are method of using 25-desacetyl rifaximin to treatgastric dyspepsia, including gastritis, gastroduodenitis, antralgastritis, antral erosions, erosive duodenitis and peptic ulcers. Theseconditions can be caused by the Helicobacter pylori. Pharmaceuticalformulations known by those of skill in the art with the benefit of thisdisclosure to be used for oral administration of a drug can be used.

Provided herein are methods of treating ear infections with 25-desacetylrifaximin. Ear infections include external ear infection, or a middleand inner ear infection. Also provided herein are methods of using25-desacetyl rifaximin to treat or prevent aspiration pneumonia and/orsepsis, including the prevention of aspiration pneumonia and/or sepsisin patients undergoing acid suppression or undergoing artificial enteralfeedings via a Gastrostomy/Jejunostomy or naso/oro gastric tubes;prevention of aspiration pneumonia in patients with impairment of mentalstatus, for example, for any reason, for subjects undergoing anesthesiaor mechanical ventilation that are at high risk for aspirationpneumonia. Provided herein are methods to treat or to preventperiodontal conditions, including plaque, tooth decay and gingivitis.Provided herein are methods of treating rosacea, which is a chronic skincondition involving inflammation of the cheeks, nose, chin, forehead, oreyelids.

Treatment of Bowel Related Disorders

In some embodiments, provided herein are methods of treating,preventing, or alleviating bowel related disorders. Such methods includeadministering to a subject in need thereof an effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof. Bowel related disorders include, for example, one ormore of irritable bowel syndrome (IBS), diarrhea, microbe associateddiarrhea, infectious diarrhea, Clostridium, Clostridium difficiledisease, travelers' diarrhea, small intestinal bacterial overgrowth(SIBO), Crohn's disease, diverticular disease, pancreatitis (includingchronic), pancreatic insufficiency, enteritis, colitis (including,ulcerative colitis), antibiotic associated colitis, hepaticencephalopathy (or other diseases which lead to increased ammonialevels), gastric dyspepsia, cirrhosis, polycystic liver disease,pouchitis, peritonitis, inflammatory bowel disease, H. pylori infection.In one embodiment, the subject is suffering from at least one bowelrelated disorder selected from irritable bowel syndrome, travelers'diarrhea, small intestinal bacterial overgrowth, Crohn's disease,chronic pancreatitis, pancreatic insufficiency, enteritis and colitis.

In some embodiments, provided herein are methods of treating,preventing, or alleviating bowel related disorders in a subjectsuffering from hepatic insufficiency. Such methods include administeringto a subject in need thereof an effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt, solvate or hydratethereof. A subject “suffering from hepatic insufficiency” as used hereinincludes subjects diagnosed with a clinical decrease in liver function,for example, due to hepatic encephalopathy, hepatitis, or cirrhosis.Hepatic insufficiency can be quantified using any of a number of scalesincluding a model end stage liver disease (MELD) score, a Child-Pughscore, or a Conn score.

In some embodiments, provided herein are methods for treating orpreventing traveler's diarrhea in a subject. Traveler's diarrhea refersto gastrointestinal illness common amongst travelers. According to theCDC, travelers' diarrhea (TD) is the most common illness affectingtravelers. Each year between 20%-50% of international travelers, anestimated 10 million persons, develop diarrhea. The onset of travelers'diarrhea usually occurs within the first week of travel but can occur atany time while traveling, and even after returning home. Risk is oftendependent on destination though other risk factors are possible. Forexamples of the use of rifaximin to treat Travelers' diarrhea, seeInfante R M, et al. 2004. Clinical Gastroenterology and Hepatology2:135-138 and Steffen R, M.D. et al. 2003. The American Journal ofGastroenterology 98(5), each of which is incorporated herein byreference in its entirety.

The illness usually results in increased frequency, volume, and weightof stool. Altered stool consistency also is common. A traveler canexperience, for example, four to five loose or watery bowel movementseach day. Other commonly associated symptoms are nausea, vomiting,diarrhea, abdominal cramping, bloating, fever, urgency, and malaise.Most cases are benign and resolve in 1-2 days without treatment, and TDis rarely life-threatening. The natural history of TD is that 90% ofcases resolve within 1 week, and 98% resolve within 1 month.

Infectious agents are the primary cause of TD. The majority of cases arecaused by bacterial, viral or protozoan infection. Bacterialenteropathogens cause approximately 80% of TD cases. The most commoncausative agent isolated in countries surveyed has been enterotoxigenicEscherichia coli (ETEC). ETEC produce watery diarrhea with associatedcramps and low-grade or no fever. Besides ETEC and other bacterialpathogens, a variety of viral and parasitic enteric pathogens also arepotential causative agents. In some embodiments, the traveler's diarrheais caused by exposure to E. Coli.

In some embodiments, provided herein are methods for treating orpreventing hepatic encephalopathy in a subject. Hepatic encephalopathy(portal-systemic encephalopathy, liver encephalopathy, hepatic coma) isa deterioration of brain function that occurs because toxic substancesnormally removed by the liver build up in the blood and reach the brain.Substances absorbed into the bloodstream from the intestine pass throughthe liver, where toxins are normally removed. In hepatic encephalopathy,toxins are not removed because liver function is impaired. Once in braintissue, the compounds produce alterations of neurotransmission thataffect consciousness and behavior. There are 4 progressive stages ofimpairment associated with HE that are defined by using the West Havencriteria (or Conn score) which range from Stage 0 (lack of detectablechanges in personality) to Stage 4 (coma, decerebrate posturing, dilatedpupils). In the earliest stages, the person's mood may change, judgmentmay be impaired, and normal sleep patterns may be disturbed. As thedisorder progresses, the person usually becomes drowsy and confused, andmovements become sluggish. Symptoms of hepatic encephalopathy caninclude impaired cognition, reduced alertness and confusion, a flappingtremor (asterixis), and a decreased level of consciousness includingcoma (e.g., hepatic coma), cerebral edema, and, possibly, death. Hepaticencephalopathy is commonly called hepatic coma or portal-systemicencephalopathy in the literature.

In some embodiments, provided herein are methods for treating irritablebowel syndrome in a subject. Irritable bowel syndrome (IBS) is adisorder that affects the motility (muscle contractions) of the colon.Sometimes called “spastic colon” or “nervous colitis,” IBS is notcharacterized by intestinal inflammation. IBS is a functional boweldisorder characterized by chronic abdominal pain, discomfort, bloating,and alteration of bowel habits. IBS can begin after an infection(post-infectious, IBS-PI) or without any other medical indicators.

In some embodiments, provided herein are methods for alleviating thesymptoms of bloating, gas or flatulence in a subject. In certainembodiments the symptoms of bloating, gas or flatulence are caused bybacterial exposure. In other embodiments, the symptoms of bloating, gasor flatulence are not caused by bacterial exposure.

In some embodiments, provided herein are methods of treating orpreventing a pathology in a subject suspected of being exposed to abiological warfare agent.

In some embodiments, treatment of a bowel related disorder includesprophylactic treatment. The identification of subjects who are in needof prophylactic treatment of a bowel related disorder is well within theability and knowledge of one skilled in the art. Certain of the methodsfor identification of subjects which are at risk of developing a bowelrelated disorder (e.g., subjects that can be treated by the methodsdescribed herein) are appreciated in the medical arts, such as familyhistory, travel history, expected travel plans and the presence of riskfactors associated with the development of that disease state in thesubject. A clinician skilled in the art can readily identify suchcandidate subjects, by the use of, for example, clinical tests, physicalexamination and medical/family/travel history.

Formulations are provided to a subject in an effective amount. The term“effective amount” includes an amount effective, at dosages and forperiods of time necessary, to achieve the desired result without beingtoxic. In one embodiment, the desired result is inhibiting a virus, orin prolonging the survivability of a subject with such a viralinfection. In another embodiment, the desired result is inhibiting abacterial infection or prolonging the survival of a subject with such abacterial infection beyond that expected in the absence of suchtreatment. An effective amount can be provided in one or a series ofadministrations.

An effective amount of 25-desacetyl rifaximin or a pharmaceuticallyacceptable salt, solvate or hydrate thereof (e.g., purified or isolated25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof) can vary according to factors such as the diseasestate, age, and weight of the subject, and the ability of the compoundto elicit a desired response in the subject. An effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof can also vary according to other factors such asintended travel destination of a subject, including but not limited to,Latin America, Africa, the Middle East, and Asia, including bothdeveloped, undeveloped and developing areas therein. An effective amountof 25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvateor hydrate thereof can further vary according to other risk-factors asubject may have, including, but not limited to, young age, advancedage, immunosuppression, diagnosis of inflammatory-bowel disease ordiabetes, and prior treatment with H-2 blockers or antacids. Dosageregimens can be adjusted to provide the optimum therapeutic response.

The dosage for in vivo therapeutics or diagnostics will generally vary.The effective amount can be determined by a physician on a case-by-casebasis and is within the skill of one in the art. Several factors can betaken into account when determining an appropriate dosage. These factorsinclude age, sex and weight of the patient, route of administration, thecondition being treated, and the severity of the condition. In someembodiments, suitable dosages and formulations of 25-desacetyl rifaximinor a pharmaceutically acceptable salt, solvate or hydrate thereof can beempirically determined by the administering physician. Standard texts,such as Remington: The Science and Practice of Pharmacy, 17th edition,Mack Publishing Company, and the Physician's Desk Reference, each ofwhich are incorporated herein by reference, can be consulted to preparesuitable compositions and doses for administration. Suitable dosages canalso be based upon the text and documents cited herein. A determinationof the appropriate dosage is within the skill of one in the art giventhe parameters for use described herein.

In some embodiments, an effective amount is an amount that is sufficientto palliate, ameliorate, stabilize, reverse or slow the progression ofirritable bowel syndrome, diarrhea, microbe associated diarrhea,Clostridium difficile associated diarrhea, travelers' diarrhea, smallintestinal bacterial overgrowth, Crohn's disease, antibiotic associatedcolitis, diverticular disease, chronic pancreatitis, pancreaticinsufficiency, enteritis, colitis, hepatic encephalopathy, pouchitis,the symptoms of any of the foregoing, or to reduce the symptoms of gas,bloating or flatulence no matter the cause. An effective amount can alsobe an amount that is sufficient to prevent irritable bowel syndrome,diarrhea, microbe associated diarrhea, Clostridium difficile associateddiarrhea, travelers' diarrhea, small intestinal bacterial overgrowth,Crohn's disease, chronic pancreatitis, pancreatic insufficiency,enteritis, colitis, hepatic encephalopathy, pouchitis, the symptoms ofany of the foregoing, gas, bloating or flatulence.

The dosage of 25-desacetyl rifaximin or a pharmaceutically acceptablesalt, solvate or hydrate thereof can vary from about 10 mg to about 10 gper day; about 20 mg to about 5 g per day; about 50 mg to about 1 g perday; about 200 mg to about 2500 mg per day or about 100 mg to about 500mg per day. Ascertaining dosage ranges is well within the skill of onein the art. The dosage of 25-desacetyl rifaximin or a pharmaceuticallyacceptable salt, solvate or hydrate thereof can range from about 0.05 to150 mg/kg of body weight. Ranges intermediate to the above-recitedvalues are also intended to be part of the present teachings. Suchdosages can vary, for example, depending on whether multipleadministrations are given, tissue type and route of administration, thecondition of the individual, the desired objective and other factorsknown to those of skill in the art. Administrations can be conductedinfrequently, or on a regular weekly basis until a desired, measurableparameter is detected, such as diminution of disease symptoms.Administration can then be diminished, such as to a biweekly or monthlybasis, as appropriate.

The length of treatment for a bowel related disorder can be from aboutan hour or two to about a year or more. The length of treatment for abowel related disorder can be for the remainder of a subject's life. Forexample, in some embodiments, the length of treatment is about 1 hour,about 2 hours, about 5 hours, about 12 hours, about 1 day, about 2 days,about 3 days, about 5 days, about 15 days, about 1 month, about 2months, about 3 months, about 6 months, about 9 months or about 1 year.The length of treatment for a particular bowel related disorder willdepend, at least in part, on the disorder. For example, travelers'diarrhea may only require treatment duration of 12 to about 72 hours,while Crohn's disease may require treatment durations from about 2 daysto 3 months. A treatment for hepatic encephalopathy can be, for example,for the remainder of the subject's life. A treatment for IBS can beintermittent for weeks or months at a time or for the remainder of thesubject's life. Dosages can also vary depending on the disease state, asdescribed in more detail herein.

In some embodiments, the 25-desacetyl rifaximin or a pharmaceuticallyacceptable salt, solvate or hydrate thereof is administered to thesubject using a composition that provides sustained delivery of the25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof to a subject. For example, sustained delivery can bedelivery for at least 12 hours, at least 24 hours, at least 36 hours, atleast 48 hours, at least one week, at least two weeks, at least threeweeks, or at least four weeks after the composition is administered tothe subject.

In some embodiments, provided herein are methods for treating orpreventing hepatic insufficiency in a subject. Hepatic insufficiencyincludes diseases and disorders in which a subject has defectivefunctional activity of the liver. Clinically, subjects having hepaticinsufficiency have decreased, e.g., statistically significantlydecreased, liver function. Hepatic insufficiency often leads to liverfailure. One exemplary disease which manifests hepatic insufficiency ishepatic encephalopathy.

In some embodiments, the present teachings also provide methods ofassessing the efficacy of the treatment in a subject. Such methodsincludes determining the pre-treatment level of intestinal bacterialovergrowth by methods known in the art (e.g., hydrogen breath testing,biopsy, sampling of the intestinal bacteria, etc.) and thenadministering a therapeutically effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt, solvate or hydratethereof to the subject. After an appropriate period of time (e.g., afteran initial period of treatment) from the administration of the compound,e.g., 2 hours, 4 hours, 8 hours, 12 hours, or 72 hours, the level ofbacterial overgrowth is determined again. In some embodiments, the levelof bacterial overgrowth is determined periodically throughout treatment.For example, the bacterial overgrowth can be checked every few hours,days or weeks to assess the further efficacy of the treatment. Adecrease in bacterial overgrowth indicates that the treatment isefficacious. Efficacy of a treatment can be measured as reduction ofbacterial overgrowth, or can be measured in terms of a reduction ofsymptoms associated with the bowel related disorder, a stabilization ofsymptoms, or a cessation of symptoms associated with a bowel relateddisorder (for example, a reduction of nausea, bloating, diarrhea, andthe like).

The method described can be used to screen or select subjects that canbenefit from treatment with 25-desacetyl rifaximin or a pharmaceuticallyacceptable salt, solvate or hydrate thereof. In some embodiments, themodulation of the bacterial overgrowth is an indication that the subjectis likely to have a favorable clinical response to the treatment. Insome embodiments, the methods provided herein (e.g., methods of treatinga subject suffering from or susceptible to a bowel related disorder)include identifying a subject that can benefit from treatment with25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof.

The term “administration” or “administering” includes routes ofintroducing the compound(s) to a subject to perform their intendedfunction. Administration includes systemic administration as well aslocal administration. Examples of routes of administration which can beused include parenteral, oral, topical, inhalation (such as intranasalor intrapulmonary, e.g., by aerosol), rectal and intradermal (such asintramuscular, intracavity, or transdermal).

The phrases “parenteral administration” and “administered parenterally”as used herein means modes of administration other than enteral andtopical administration, usually by injection, and includes, withoutlimitation, intravenous, intramuscular, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal,transtracheal, subcutaneous, subcuticular, intraarticulare, subcapsular,subarachnoid, intraspinal and intrasternal injection and infusion.

The phrases “systemic administration,” “administered systemically”,“peripheral administration” and “administered peripherally” as usedherein mean the administration of a compound(s), drug or other material,such that it enters the patient's system and, thus, is subject tometabolism and other like processes, for example, subcutaneousadministration.

In some embodiments, provided herein are uses of a 25-desacetylrifaximin or a pharmaceutically acceptable salt, solvate or hydratethereof in therapy.

In some embodiments, the 25-desacetyl rifaximin can be used for thetreatment or prevention of infectious disorders caused by a variety ofbacterial organisms, including gram-positive, gram-negative, aerobic andanaerobic bacteria. For example, the 25-desacetyl rifaximin can be usedto treat disorders caused by abnormal GI flora, e.g., enteropathogens.Representative enteropathogens include, for example, E. coli, including,enteropathogenic E. coli (EPEC) and enterotoxigenic E. coli (ETEC),Shigella spp., Salmonella spp., Campylobacter spp., Vibrio, H. pylori,Staphylococcus spp., and C. difficile.

In some embodiments, a subject is treated with rifaximin whichmetabolizes into 25-desacetyl rifaximin in the body to yield an effectamount of 25-desacetyl rifaximin to treat the bowel related disorder. Inthis embodiment, the rifaximin can be incubated in the subject for asufficient time to yield a predetermined level of the 25-desacetylrifaximin metabolite. Alternatively, the subject can be treated bydirect administration of 25-desacetyl rifaximin.

Embodiments relate to a method of treating one or more bowel relateddisorders. Bowel related disorder, include, for example, irritable bowelsyndrome, travelers' diarrhea, small intestinal bacterial overgrowth,Crohn's disease, pancreatitis, pancreatic insufficiency, peritonitis,hepatic encephalopathy, pouchitis, infectious diarrhea, inflammatorybowel disease, diverticular disease, Clostridium, C. difficile disease,H. pylori infection, enteritis and colitis and other related conditions.

Other disorders that can be treated with 25-desacetyl rifaximin,include, for example, skin infections, bacterial vaginosis, periodontaldisease, lung infections, mucosal infections,

According to the CDC, Travelers' diarrhea is the most common illnessaffecting travelers. Each year between 20%-50% of internationaltravelers, an estimated 10 million persons, develop diarrhea. The onsetof Travelers' diarrhea can occur within the first week of travel butalso can occur at any time while traveling, and even after returninghome. Risk is often dependent on destination though other risk factorsare possible.

Traveler's diarrhea is marked by increased frequency, volume, and weightof stool. Altered stool consistency also seen in subjects. A travelercan experience, for example, four to five loose or watery bowelmovements each day. Other associated symptoms include, for example,nausea, vomiting, diarrhea, abdominal cramping, bloating, fever,urgency, and malaise.

In some embodiments, the methods further comprise administeringrehydration therapy (RT) to the subject. The RT can be administeredbefore, during and/or after the administration of the 25-desacetylrifaximin RT can include rehydrating the subject in the most efficientor the most tolerated methods. Examples include one or more of oralrehydration therapy or intravenous rehydration therapy.

Hepatic encephalopathy (e.g., portal-systemic encephalopathy, liverencephalopathy, hepatic coma) is a deterioration of brain function thatoccurs because toxic substances normally removed by the liver build upin the blood and reach the brain. Substances absorbed into thebloodstream from the intestine pass through the liver, where toxins arenormally removed. In hepatic encephalopathy, toxins are not removedbecause liver function is impaired. Symptoms include decreased brainfunction, reduced alertness and confusion. In the earliest stages, thesubject's mood may change, judgment may be impaired, and sleep patternsmay be disturbed. As the disorder progresses, the subject can becomedrowsy and confused, and movements may become sluggish. The hands cannotbe held steady when the person stretches out the arms, resulting in acrude flapping motion of the hands (asterixis).

Irritable bowel syndrome (IBS) is a disorder that affects the motility(muscle contractions) of the colon. Sometimes called “spastic colon” or“nervous colitis,” IBS is not characterized by intestinal inflammation.IBS is a functional bowel disorder characterized by chronic abdominalpain, discomfort, bloating, and alteration of bowel habits. IBS canbegin after an infection (post-infectious, IBS-PI) or without any othermedical indicators.

In some embodiments, Travelers' Diarrhea is treated in a subject byadministering an effective amount of a 25-desacetyl rifaximin or apharmaceutically acceptable salt thereof. In some embodiments, themethod comprises administering a composition comprising 25-desacetylrifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, provided herein are methods for treating orpreventing hepatic encephalopathy in a subject comprising administeringto a subject in need thereof a therapeutically effective amount of25-desacetyl rifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, provided herein are methods for alleviating thesymptoms of bloating, gas or flatulence in a subject comprisingadministering to a subject in need thereof a therapeutically effectiveamount of 25-desacetyl rifaximin or a pharmaceutically acceptable saltthereof. In some embodiments the symptoms of bloating, gas or flatulenceare caused by bacterial exposure. In some embodiments, the symptoms ofbloating, gas or flatulence are not caused by bacterial exposure.

In some embodiments, provided herein are methods for treating irritablebowel syndrome in a subject comprising administering to a subject inneed thereof a therapeutically effective amount of 25-desacetylrifaximin or a pharmaceutically acceptable salt thereof.

In some embodiments, 25-desacetyl rifaximin or pharmaceuticallyacceptable salt thereof can be administered with one or more otheradditional therapeutic agents.

In some embodiments, the 25-desacetyl rifaximin is administered with anagent for treating inflammatory bowel disease or syndrome which can beoptionally employed in combination and can including one or more ofsulfasalazine, salicylates, mesalamine, balsalazide, and the like.

For example, 25-desacetyl rifaximin can be administered or formulated incombination with other antibiotics or anti-invectives. For example, theycan be administered or formulated with a macrolide (e.g., tobramycin(Tobi®)), a cephalosporin (e.g., cephalexin (Keflex®), cephradine(Velosef®), cefuroxime (Ceftin®), cefprozil (Cefzil®), cefaclor(Ceclor®), cefixime (Suprax®) or cefadroxil (Duricef®)), aclarithromycin (e.g., clarithromycin (Biaxin®)), an erythromycin (e.g.,erythromycin (EMycin®)), a penicillin (e.g., penicillin V (V-Cillin K®or Pen Vee K®)) or a quinolone (e.g., ofloxacin (Floxin®), ciprofloxacin(Cipro®) or norfloxacin (Noroxin®)), aminoglycoside antibiotics (e.g.,apramycin, arbekacin, bambermycins, butirosin, dibekacin, neomycin,neomycin, undecylenate, netilmicin, paromomycin, ribostamycin,sisomicin, and spectinomycin), amphenicol antibiotics (e.g.,azidamfenicol, chloramphenicol, florfenicol, and thiamphenicol),ansamycin antibiotics (e.g., rifamide, rifampin, and rifaximin),carbacephems (e.g., loracarbef), carbapenems (e.g., biapenem andimipenem), cephalosporins (e.g., cefaclor, cefadroxil, cefamandole,cefatrizine, cefazedone, cefozopran, cefpimizole, cefpiramide, andcefpirome), cephamycins (e.g., cefbuperazone, cefmetazole, andcefminox), monobactams (e.g., aztreonam, carumonam, and tigemonam),oxacephems (e.g., flomoxef, and moxalactam), penicillins (e.g.,amdinocillin, amdinocillin pivoxil, amoxicillin, bacampicillin,benzylpenicillinic acid, benzylpenicillin sodium, epicillin,fenbenicillin, floxacillin, penamccillin, penethamate hydriodide,penicillin o-benethamine, penicillin 0, penicillin V, penicillin Vbenzathine, penicillin V hydrabamine, penimepicycline, andphencihicillin potassium), lincosamides (e.g., clindamycin, andlincomycin), amphomycin, bacitracin, capreomycin, colistin, enduracidin,enviomycin, tetracyclines (e.g., apicycline, chlortetracycline,clomocycline, and demeclocycline), 2,4-diaminopyrimidines (e.g.,brodimoprim), nitrofurans (e.g., furaltadone, and furazolium chloride),quinolones and analogs thereof (e.g., cinoxacin, clinafloxacin,flumequine, and grepagloxacin), sulfonamides (e.g., acetylsulfamethoxypyrazine, benzylsulfamide, noprylsulfamide,phthalylsulfacetamide, sulfachrysoidine, and sulfacytine), sulfones(e.g., diathymosulfone, glucosulfone sodium, and solasulfone),cycloserine, mupirocin, vancomycin, and tuberin.

25-desacetyl rifaximin can also be administered or formulated incombination with an antiemetic agent. Suitable antiemetic agentsinclude, for example, metoclopromide, domperidone, prochlorperazine,promethazine, chlorpromazine, trimethobenzamide, ondansetron,granisetron, hydroxyzine, acethylleucine monoethanolamine, alizapride,azasetron, benzquinamide, bietanautine, bromopride, buclizine,clebopride, cyclizine, dimenhydrinate, diphenidol, dolasetron,meclizine, methallatal, metopimazine, nabilone, oxyperndyl, pipamazine,scopolamine, sulpiride, tetrahydrocannabinols, thiethylperazine,thioproperazine, tropisetron, and mixtures thereof.

25-desacetyl rifaximin can also be administered or formulated incombination with can be formulated in combination with one or moreantiviral agents. Useful antiviral agents include, for example, proteaseinhibitors, nucleoside reverse transcriptase inhibitors, non-nucleosidereverse transcriptase inhibitors and nucleoside analogs. The antiviralagents include, for example, zidovudine, acyclovir, gangcyclovir,vidarabine, idoxuridine, trifluridine, and ribavirin, as well asfoscarnet, amantadine, rimantadine, saquinavir, indinavir, amprenavir,lopinavir, ritonavir, alpha-interferons; adefovir, clevadine, entecavir,pleconaril.

25-desacetyl rifaximin can also be formulated in combination with anantifungal agent. Suitable antifungal agents include, for example,amphotericin B, itraconazole, ketoconazole, fluconazole, intrathecal,flucytosine, miconazole, butoconazole, clotrimazole, nystatin,terconazole, tioconazole, ciclopirox, econazole, haloprogrin, naftifine,terbinafine, undecylenate, and griseofuldin.

25-desacetyl rifaximin can also be administered or formulated incombination with be formulated with aluminum carbonate, aluminumhydroxide, bismuth subsalicylate, calcium carbonate, calcium hydroxide,calcium phosphate, dihydroxyaluminum sodium carbonate, magnesiumhydroxide, magnesium oxide, magnesium trisilicate, sodium bicarbonate,simethicone, glycine, or combinations thereof.

Where present, other co-administered pharmaceutical agents can beemployed, for example, in formulations as described above and in amountsand dosing as indicated in the Physician's Desk Reference (PDR), asindicated in the prescribing information approved by a governmentregulatory agency (e.g., Food and Drug Administration, FDA or EuropeanMedicines Agency, EMEA), as recommended by the innovator of the agent oras recommend by a healthcare provider.

In some embodiments, 25-desacetyl rifaximin, for example, purified orisolated 25-desacetyl rifaximin, or a pharmaceutically acceptable salt,solvate or hydrate thereof is administered to the subject in apharmaceutically-acceptable formulation. In certain embodiments,25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof or a 25-desacetyl rifaximin pharmaceutical compositionis suitable for topical, intravenous, parental, or oral administration.The methods further include administering to a subject a therapeuticallyeffective amount of 25-desacetyl rifaximin or a pharmaceuticallyacceptable salt, solvate or hydrate thereof.

The 25-desacetyl rifaximin can be administered in the dosage forms asdescribed herein in single or divided doses of, for example, one to fourtimes daily. It can be advisable to start a patient on a low dose andwork up gradually to a high dose combination.

The phrase “pharmaceutically acceptable” refers to purified or isolated25-desacetyl rifaximin, compositions containing purified or isolated25-desacetyl rifaximin, and/or dosage forms which are, within the scopeof sound medical judgment, suitable for use in contact with the tissuesof human beings and animals without excessive toxicity, irritation,allergic response, or other problem or complication, commensurate with areasonable benefit/risk ratio.

The phrase “pharmaceutically-acceptable carrier” includespharmaceutically-acceptable material, composition or vehicle, involvedin carrying or transporting the subject chemical from one organ, orportion of the body, to another organ, or portion of the body. Eachcarrier is “acceptable” in the sense of being compatible with the otheringredients of the formulation and not injurious to the patient.

Methods of preparing these compositions include bringing intoassociation 25-desacetyl rifaximin or a pharmaceutically acceptablesalt, solvate or hydrate thereof and a carrier and, optionally, one ormore accessory ingredients. These compositions can also containadjuvants such as preservatives, wetting agents, emulsifying agents anddispersing agents.

Regardless of the route of administration selected, 25-desacetylrifaximin, which can be used in a suitable salt, solvate, or hydrateform, and/or the pharmaceutical compositions of 25-desacetyl rifaximin,are formulated into pharmaceutically acceptable dosage forms by methodsknown to those of skill in the art.

Formulations are provided to a subject in an effective amount. The term“effective amount” includes an amount effective, at dosages and forperiods of time necessary, to achieve the desired result. An effectiveamount of purified or isolated 25-desacetyl rifaximin can vary accordingto factors such as the disease state, age, and weight of the subject,and the ability of the compound to elicit a desired response in thesubject. An effective amount of 25-desacetyl rifaximin can varyaccording to other factors such as intended travel destination of asubject, including for example, Latin America, Africa, the Middle East,and Asia, including both developed, undeveloped and developing areastherein. An effective amount of 25-desacetyl rifaximin can varyaccording other risk-factors a subject can have including, for example,young age, advanced age, immunosuppression, diagnosis ofinflammatory-bowel disease or diabetes, and prior treatment with H-2blockers or antacids. Dosage regimens can be adjusted to provide theoptimum therapeutic response.

The effective amount is generally determined by the physician on acase-by-case basis and is within the skill of one in the art. As a rule,the dosage for in vivo therapeutics or diagnostics will vary. Severalfactors, among others, can be taken into account when determining anappropriate dosage. These factors include age, sex and weight of thepatient, the condition being treated, and the severity of the condition.The length of treatment for a particular bowel disorder will depend, inpart, on the disorder. For example, travelers' diarrhea may only requiretreatment duration of 12 to about 72 hours, while Crohn's disease mayrequire treatment durations from about 2 days to 3 months. Hepaticencephalopathy may be treated for the remainder of a subject's lifeafter diagnosis. IBS, for example, can be treated for two weeks to twomonths or longer. Subjects can also be retreated with 25-desacetylrifaximin as necessary. Dosages of rifaximin will also vary depending onthe diseases state. Exemplary dosage ranges are provided herein infra.

The identification of those subjects who are in need of prophylactictreatment for bowel disorder is well within the ability and knowledge ofone skilled in the art. Certain of the methods for identification ofsubjects which are at risk of developing a bowel disorder which can betreated by the subject method are appreciated in the medical arts, suchas family history, travel history and expected travel plans, thepresence of risk factors associated with the development of that diseasestate in the subject. A clinician skilled in the art can readilyidentify such candidate subjects, by the use of, for example, clinicaltests, physical examination and medical/family/travel history.

Suitable dosages and formulations of 25-desacetyl rifaximin or apharmaceutically acceptable salt, solvate or hydrate thereof can beempirically determined by the administering physician. Standard texts,such as Remington: The Science and Practice of Pharmacy, 17th edition,Mack Publishing Company, and the Physician's Desk Reference, each ofwhich are incorporated herein by reference, can be consulted to preparesuitable compositions and doses for administration. A determination ofthe appropriate dosage is within the skill of one in the art given theparameters for use described herein.

Standard texts, such as Remington: The Science and Practice of Pharmacy,17th edition, Mack Publishing Company, incorporated herein by reference,can be consulted to prepare suitable compositions and formulations foradministration, without undue experimentation. Suitable dosages can alsobe based upon the text and documents cited herein. A determination ofthe appropriate dosages is within the skill of one in the art given theparameters herein.

In terms of treatment, an effective amount is an amount that issufficient to palliate, ameliorate, stabilize, reverse or slow theprogression of one or more bowel related disorders or entericinfections, the symptoms of any thereof, or to reduce the symptoms ofpain, gas, bloating or flatulence. A therapeutically effective amountcan be provided in one or a series of administrations. The effectiveamount is generally determined by the physician on a case-by-case basisand is within the skill of one in the art.

As a rule, the dosage for in vivo therapeutics or diagnostics will vary.Several factors may be taken into account when determining anappropriate dosage. These factors include, for example, age, sex andweight of the patient, the condition being treated, and the severity ofthe condition.

The dosage of 25-desacetyl rifaximin or a pharmaceutically acceptablesalt, solvate or hydrate thereof can vary from about 10 mg to about 10 gper day; about 20 mg to about 5 g per day; about 50 mg to about 2 g perday; or about 100 mg to about 600 mg per day. Dosages between theseranges are also included herein, for example, a dosage of 1650 mg/day ora dosage of 1100 mg/day. Ascertaining dosage ranges is well within theskill of one in the art. The dosage of 25-desacetyl rifaximin or apharmaceutically acceptable salt, solvate or hydrate thereof can rangefrom about 0.05 to 150 mg/kg of body weight. Such dosages can vary, forexample, depending on whether multiple administrations are given, tissuetype and route of administration, the condition of the individual, thedesired objective and other factors known to those of skill in the art.Administrations can be conducted infrequently, or on a regular weeklybasis until a desired, measurable parameter is detected, such asdiminution of disease symptoms. Administration can then be diminished,such as to a biweekly or monthly basis, as appropriate.

A therapeutically effective amount can be administered in one or moredoses. The term “administration” or “administering” includes routes ofintroducing the compound(s) to a subject to perform their intendedfunction. Examples of routes of administration which can be used includeinjection (subcutaneous, intravenous, parenterally, intraperitoneally,intrathecal), oral, inhalation, rectal and transdermal.

The phrases “parenteral administration” and “administered parenterally”as used herein means modes of administration other than enteral andtopical administration, for example, by injection, and includes, withoutlimitation, intravenous, intramuscular, intraarterial, intrathecal,intracapsular, intraorbital, intracardiac, intradermal, intraperitoneal,transtracheal, subcutaneous, subcuticular, intraarticulare, subcapsular,subarachnoid, intraspinal and intrasternal injection and infusion.

The phrases “systemic administration,” “administered systemically”,“peripheral administration” and “administered peripherally” as usedherein mean the administration of a compound(s), drug or other material,such that it enters the patient's system and, thus, is subject tometabolism and other like processes, for example, subcutaneousadministration.

Available routes of administration include subcutaneous, intramuscular,intraperitoneal, intradermal, oral, intranasal, intrapulmonary (e.g., byaerosol), intravenously, intramuscularly, subcutaneously, intracavity,intrathecally or transdermally, alone or in combination with otherpharmaceutical agents.

25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof and compositions comprising 25-desacetyl rifaximin thatare suitable for oral administration can be presented as discrete dosageforms, such as, for example, tablets (e.g., chewable tablets), caplets,capsules, and liquids (e.g., flavored syrups). Such dosage forms containpredetermined amounts of active ingredients, and can be prepared bymethods of pharmacy well known to those skilled in the art. Seegenerally, Remington's Pharmaceutical Sciences, 18th ed., MackPublishing, Easton Pa. (1990).

Oral dosage forms can be prepared, for example, by combining the activeingredient(s) in an intimate admixture with at least one excipient.Excipients can take a wide variety of forms depending on the form ofpreparation desired for administration. For example, excipients suitablefor use in oral liquid or aerosol dosage forms include, for example,water, glycols, oils, alcohols, flavoring agents, preservatives, andcoloring agents. Examples of excipients suitable for use in solid oraldosage forms (e.g., powders, tablets, capsules, and caplets) include,for example, starches, sugars, micro-crystalline cellulose, diluents,granulating agents, lubricants, binders, and disintegrating agents. Ifdesired, tablets can be coated by standard aqueous or nonaqueoustechniques. Such dosage forms can be prepared by any of the methods ofpharmacy.

Examples of excipients that can be used in oral dosage forms include,for example for example, binders, fillers, disintegrants, andlubricants. Binders suitable for use in pharmaceutical compositions anddosage forms include, for example, corn starch, potato starch, or otherstarches, gelatin, natural and synthetic gums such as acacia, sodiumalginate, alginic acid, other alginates, powdered tragacanth, guar gum,cellulose and its derivatives (e.g., ethyl cellulose, cellulose acetate,carboxymethyl cellulose calcium, sodium carboxymethyl cellulose),polyvinyl pyrrolidone, methyl cellulose, pre-gelatinized starch,hydroxypropyl methyl cellulose, (e.g., nos. 2208, 2906, 2910),microcrystalline cellulose, and mixtures thereof.

Examples of fillers suitable for use in the pharmaceutical compositionsand dosage forms disclosed herein include, for example, talc, calciumcarbonate (e.g., granules or powder), microcrystalline cellulose,powdered cellulose, dextrates, kaolin, mannitol, silicic acid, sorbitol,starch, pre-gelatinized starch, and mixtures thereof. The binder orfiller in pharmaceutical compositions may, for example, be present fromabout 50 to about 99 weight percent of the pharmaceutical composition ordosage form.

Suitable forms of microcrystalline cellulose include, for example, thematerials sold as AVICEL-PH-101, AVICEL-PH-103 AVICEL RC-581,AVICEL-PH-105 (available from FMC Corporation, American ViscoseDivision, Avicel Sales, Marcus Hook, Pa.), and mixtures thereof. Aspecific binder is a mixture of microcrystalline cellulose and sodiumcarboxymethyl cellulose sold as AVICEL RC-581. Suitable anhydrous or lowmoisture excipients or additives include AVICEL-PH-103™ and Starch 1500LM.

Disintegrants can be used to provide tablets that disintegrate whenexposed to an aqueous environment. Compositions herein can comprise fromabout 0.5 to about 15 weight percent of disintegrant, specifically fromabout 1 to about 5 weight percent of disintegrant.

Lubricants that can be used in pharmaceutical compositions and dosageforms described herein can include, for example, calcium stearate,magnesium stearate, mineral oil, light mineral oil, glycerin, sorbitol,mannitol, polyethylene glycol, other glycols, stearic acid, sodiumlauryl sulfate, talc, hydrogenated vegetable oil (e.g., peanut oil,cottonseed oil, sunflower oil, sesame oil, olive oil, corn oil, andsoybean oil), zinc stearate, ethyl oleate, ethyl laureate, agar, andmixtures thereof. Additional lubricants include, for example, a syloidsilica gel (AEROSIL 200, manufactured by W. R. Grace Co. of Baltimore,Md.), a coagulated aerosol of synthetic silica (marketed by Degussa Co.of Plano, Tex.), CAB-O-SIL (a pyrogenic silicon dioxide product sold byCabot Co. of Boston, Mass.), and mixtures thereof.

Parenteral and intravascular dosage forms can be administered tosubjects by various routes including, for example, subcutaneous,intravenous (including bolus injection and constant infusion),intramuscular, and intraarterial. Examples of parenteral dosage formsinclude, for example, solutions ready for injection, dry products(including, for example lyophilized powders, pellets, and tablets) readyto be dissolved or suspended in a pharmaceutically acceptable vehiclefor injection, suspensions ready for injection, and emulsions.

Suitable vehicles that can be used to provide parenteral dosage formsare well known to those skilled in the art. Examples include, forexample: Water for Injection USP; aqueous vehicles such as, for example,Sodium Chloride Injection, Ringer's Injection, Dextrose Injection,Dextrose and Sodium Chloride Injection, and Lactated Ringers Injection;water-miscible vehicles such as, for example, ethyl alcohol,polyethylene glycol, and polypropylene glycol; and non-aqueous vehiclessuch as, for example, corn oil, cottonseed oil, peanut oil, sesame oil,ethyl oleate, isopropyl myristate, and benzyl benzoate.

Transdermal, topical, and mucosal dosage forms can include, for example,ophthalmic solutions, sprays, aerosols, creams, lotions, ointments,gels, solutions, emulsions, suspensions, or other forms known to one ofskill in the art. See, e.g., Remington's Pharmaceutical Sciences, 16thand 18th eds., Mack Publishing, Easton Pa. (1980 & 1990); andIntroduction to Pharmaceutical Dosage Forms, 4th ed., Lea & Febiger,Philadelphia (1985). Dosage forms suitable for treating mucosal tissueswithin the oral cavity can be formulated as mouthwashes or as oral gels.Further, transdermal dosage forms include “reservoir type” or “matrixtype” patches, which can be applied to the skin and worn for a specificperiod of time to permit the penetration of a desired amount of activeingredients. Dosage forms can also be administered in the form ofsuppositories for rectal administration of the drug. These compositionscan be prepared by mixing the compound with a suitable non-irritationexcipient which is solid at ordinary temperatures but liquid at therectal temperature and will therefore melt in the rectum to release thecompound. Such materials are, for example, cocoa butter and polyethyleneglycol.

Depending on the specific tissue to be treated, additional componentscan be used prior to, in conjunction with, or subsequent to treatmentwith 25-desacetyl rifaximin. For example, penetration enhancers can beused to assist in delivering the active ingredients to the tissue.Suitable penetration enhancers include, for example: acetone; variousalcohols such as ethanol, oleyl, and tetrahydrofuryl; alkyl sulfoxidessuch as dimethyl sulfoxide; dimethyl acetamide; dimethyl formamide;polyethylene glycol; pyrrolidones such as polyvinylpyrrolidone; Kollidongrades (Povidone, Polyvidone); urea; and various water-soluble orinsoluble sugar esters such as Tween 80 (polysorbate 80) and Span 60(sorbitan monostearate).

Although methods and materials similar or equivalent to those describedherein can be used in the composition described herein, certain methodsand materials are described herein. The materials, methods, and examplesare illustrative only and not intended to be limiting. Other featuresand advantages of the 25-desacetyl rifaximin and compositions thereofwill be apparent from the detailed description and from the claims.

Kits

Provided herein are kits which, when used by the medical practitioner,can simplify the identification of subjects and the administration ofappropriate amounts of 25-desacetyl rifaximin and/or a pharmaceuticallyacceptable salt, solvate or hydrate thereof to a patient.

One kit provided herein comprises one or more unit dosage forms of25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof, and instructions for identification of a subject.

Kits can further comprise devices that are used to administer25-desacetyl rifaximin or a pharmaceutically acceptable salt, solvate orhydrate thereof. Examples of such devices include, for example,intravenous cannulation devices, syringes, drip bags, patches, topicalgels, pumps, containers that provide protection from photodegredation,autoinjectors, and inhalers.

Kits can further comprise pharmaceutically acceptable vehicles that canbe used to administer one or more active ingredients. For example, if anactive ingredient is provided in a solid form that is reconstituted forparenteral administration, the kit can comprise a sealed container of asuitable vehicle in which the active ingredient can be dissolved to forma particulate-free sterile solution that is suitable for parenteraladministration. Examples of pharmaceutically acceptable vehiclesinclude, for example: Water for Injection USP; aqueous vehicles such as,for example for example, Sodium Chloride Injection, Ringer's Injection,Dextrose Injection, Dextrose and Sodium Chloride Injection, and LactatedRinger's Injection; water-miscible vehicles such as, for example, ethylalcohol, polyethylene glycol, and polypropylene glycol; and non-aqueousvehicles such as, for example, corn oil, cottonseed oil, peanut oil,sesame oil, ethyl oleate, isopropyl myristate, and benzyl benzoate.

EXAMPLES

To more fully understand the 25-desacetyl rifaximin and compositionsthereof, the following examples are provided. It should be understoodthat these examples are for illustrative purposes only and are not to beconstrued as limiting in any way.

Example 1 Preparation of 25-Desacetyl Rifaximin

A reaction to prepare 25-Desacetyl Rifaximin was carried out accordingto Scheme 1 shown below.

Removal of the 25-acetyl moiety using 2M NaOH in methanol proceededsmoothly at room temperature. Acidification of the mixture to pH=4 gavethe desired 25-desacetyl rifaximin. Initial small scale experimentsindicated that water is beneficial to producing filterable solids, thusdilute HCl (1 M in water) was used to acidify the mixture. Purificationof the crude material (˜95% AUC) was accomplished by trituration of thecrude solid with water/methanol (2:1), giving product with an HPLCpurity of 97.9% (AUC).

Rifaximin (100 g, 0.127 moles, 1 eq.) was added to a stirring solutionof MeOH at room temperature (18-21° C.) and stirred for 5 minutes. A 2MNaOH solution (318 mL, 0.636 moles, 5 eq) was added over 2-3 min and themixture turns from an orange suspension to a darker colored solution.The reaction mixture was stirred 3 h at ambient temperature (19-25° C.)after which time HPLC analysis shows little or no starting material. Thereaction was quenched by adjusting the pH of the mixture to pH=4 using1M HCl, while maintaining the temperature below 30° C. The resultantsuspension was stirred at ambient temperature (19-27° C.) for 1.5 h thenfiltered through a Buchner funnel and washed with H₂O (2×50 mL) followedby 2×100 mL of MTBE and lastly 50 mL of EtOAc. The crude orange-brownsolid was dried in a vacuum oven (35-40° C., >29.5″ Hg) to give 79 g ofcrude 25-desacetyl rifaximin.

Crude des-acetyl rifaximin (75 g) was suspended in 375 mL of H₂O/MeOH(2:1) and stirred for 1 h. The mixture was filtered and the solids werewashed with H₂O (70 mL) followed by MTBE (70 mL), then dried in a vacuumoven (18-20° C., >29.5″ Hg) overnight (17 h) to give 70.5 g of purifieddes-acetyl rifaximin (HPLC Purity (AUC)=97.9%, LC/MS (M+)=744.

Rifaximin can also be desacetylated to 25 desacetyl rifaximin using anydesacetylation techniques known in the art. The desacetylation can beaccomplished by hydrolyzing the CH₂COO group linked to C₂₅ of therifaximin molecules. The hydrolysis process can be accomplished bytreating the rifaximin dissolved in a suitable alkaline solvent. Thealkalizing agents include, for example, hydroxides, organic bases,bicarbonates, and the like.

Example 2 Bacterial Activity Assays

Bacteria Compound Class Dose Criteria Results Enterococcus faecalis25-desacetyl Gram 10 μg/mL +/− + (VRE, ATCC 51575) rifaximin PositiveRifaximin Gram 10 μg/mL +/− + Positive Escherichia coli Rifaximin Gram 3μg/mL +/− + (ATCC 10536) Negative Escherichia coli Rifaximin Gram 10μg/mL +/− + (ATCC 25922) Negative Escherichia coli Rifaximin Gram 10μg/mL +/− + (Juhl) Negative Enterobacter cloacae Rifaximin Gram 100μg/mL +/− + (ATCC 13047) Negative Pseudomonas Rifaximin Gram 10 μg/mL+/− + aeruginosa (ATCC 9027) Negative Clostridium 25-desacetyl Anaerobes1 μg/mL +/− + sporogenes (ATCC 7955) rifaximin Clostridium RifaximinAnaerobes 0.03 μg/mL +/− + sporogenes (ATCC 7955) Clostridium defficile25-desacetyl Anaerobes 0.3 μg/mL +/− + (ATCC 9689) rifaximin RifaximinAnaerobes 0.03 μg/mL +/− + Clostridium 25-desacetyl Anaerobes 0.03 μg/mL+/− + perfringens (ATCC 13124) rifaximin Rifaximin Anaerobes 0.03 μg/mL+/− + Helicobacter pylori Rifaximin Anaerobes 3 μg/mL +/− + (ATCC 43504)

Bacteria Compound Class Route N = Concentration Criteria ResultBacteroides 25- Anaerobes in vitro 2 100 μg/mL  +/− − fragilis desacetyl2 30 μg/mL +/− − (ATCC 23745) rifaximin 2 10 μg/mL +/− − 1141022 2  3μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 20.03 μg/mL  +/− − Rifaximin Anaerobes in vitro 2 100 μg/mL  +/− −1141023 2 30 μg/mL +/− − 2 10 μg/mL +/− − 2  3 μg/mL +/− − 2  1 μg/mL+/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− −Clostridium ″25- Anaerobes in vitro 2 100 μg/mL  +/− + difficiledesacetyl (ATCC 9689) rifaximin 1141022 ″25- 2 30 μg/mL +/− + desacetylrifaximin 1141022 ″25- 2 10 μg/mL +/− + desacetyl rifaximin 1141022 ″25-2  3 μg/mL +/− + desacetyl rifaximin 1141022 ″25- 2  1 μg/mL +/− +desacetyl rifaximin 1141022 ″25- 2 0.3 μg/mL  +/− + desacetyl rifaximin1141022 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − ″Rifaximin Anaerobes invitro 2 100 μg/mL  +/− + 1141023 ″Rifaximin 2 30 μg/mL +/− + 1141023″Rifaximin 2 10 μg/mL +/− + 1141023 ″Rifaximin 2  3 μg/mL +/− + 1141023″Rifaximin 2  1 μg/mL +/− + 1141023 ″Rifaximin 2 0.3 μg/mL  +/− +1141023 ″Rifaximin 2 0.1 μg/mL  +/− + 1141023 ″Rifaximin 2 0.03 μg/mL +/− + 1141023 Clostridium ″25- Anaerobes in vitro 2 100 μg/mL  +/− +perfringens desacetyl (ATCC 13124) rifaximin 1141022 ″25- 2 30 μg/mL+/− + desacetyl rifaximin 1141022 ″25- 2 10 μg/mL +/− + desacetylrifaximin 1141022 ″25- 2  3 μg/mL +/− + desacetyl rifaximin 1141022 ″25-2  1 μg/mL +/− + desacetyl rifaximin 1141022 ″25- 2 0.3 μg/mL  +/− +desacetyl rifaximin 1141022 ″25- 2 0.1 μg/mL  +/− + desacetyl rifaximin1141022 ″25- 2 0.03 μg/mL  +/− + desacetyl rifaximin 1141022 ″RifaximinAnaerobes in vitro 2 100 μg/mL  +/− + 1141023 ″Rifaximin 2 30 μg/mL+/− + 1141023 ″Rifaximin 2 10 μg/mL +/− + 1141023 ″Rifaximin 2  3 μg/mL+/− + 1141023 ″Rifaximin 2  1 μg/mL +/− + 1141023 ″Rifaximin 2 0.3μg/mL  +/− + 1141023 ″Rifaximin 2 0.1 μg/mL  +/− + 1141023 ″Rifaximin 20.03 μg/mL  +/− + 1141023 620500 ″25- Anaerobes in vitro 2 100 μg/mL +/− + Clostridium desacetyl sporogenes rifaximin (ATCC 7955) 1141022″25- 2 30 μg/mL +/− + desacetyl rifaximin 1141022 ″25- 2 10 μg/mL +/− +desacetyl rifaximin 1141022 ″25- 2  3 μg/mL +/− + desacetyl rifaximin1141022 ″25- 2  1 μg/mL +/− + desacetyl rifaximin 1141022 2 0.3 μg/mL +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − ″Rifaximin Anaerobes invitro 2 100 μg/mL  +/− + 1141023 ″Rifaximin 2 30 μg/mL +/− + 1141023″Rifaximin 2 10 μg/mL +/− + 1141023 ″Rifaximin 2  3 μg/mL +/− + 1141023″Rifaximin 2  1 μg/mL +/− + 1141023 ″Rifaximin 2 0.3 μg/mL  +/− +1141023 ″Rifaximin 2 0.1 μg/mL  +/− + 1141023 ″Rifaximin 2 +/− + 1141023611500 25- Gram Negative in vitro 2 100 μg/mL  +/− − Enterobacterdesacetyl 2 30 μg/mL +/− − cloacae rifaximin 2 10 μg/mL +/− − (ATCC13047) 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL +/− − 2 0.03 μg/mL  +/− − Rifaximin Gram Negative in vitro 2 100 μg/mL +/− + 2 30 μg/mL +/− − 2 10 μg/mL +/− − 2  3 μg/mL +/− − 2  1 μg/mL +/−− 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − 602100 25-Gram Positive in vitro 2 100 μg/mL  +/− + Enterococcus desacetyl 2 30μg/mL +/− + faecalis rifaximin 2 10 μg/mL +/− + (VRE, ATCC 51575)″ 2  3μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 20.03 μg/mL  +/− − Rifaximin Gram Positive in vitro 2 100 μg/mL  +/− + 230 μg/mL +/− + 2 10 μg/mL +/− + 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − 610000 25- GramNegative in vitro 2 100 μg/mL  +/− − Escherichia desacetyl 2 30 μg/mL+/− − coli rifaximin 2 10 μg/mL +/− − (ATCC 10536) 2  3 μg/mL +/− − 2  1μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− −Rifaximin Gram Negative in vitro 2 100 μg/mL  +/− + ″ 2 30 μg/mL +/− + ″2 10 μg/mL +/− + ″ 2  3 μg/mL +/− + 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− −2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − 610100 25- Gram Negative in vitro2 100 μg/mL  +/− − Escherichia desacetyl 2 30 μg/mL +/− − coli rifaximin2 10 μg/mL +/− − (ATCC 25922) 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − Rifaximin GramNegative in vitro 2 100 μg/mL  +/− + ″ 2 30 μg/mL +/− + ″ 2 10 μg/mL+/− + 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL +/− − 2 0.03 μg/mL  +/− − 611000 25- Gram Negative in vitro 2 100 μg/mL +/− − Escherichia desacetyl 2 30 μg/mL +/− − coli (Juhl) rifaximin 2 10μg/mL +/− − 1141021 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL  +/− −2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − ″Rifaximin Gram Negative in vitro2 100 μg/mL  +/− + 1141022 ″Rifaximin 2 30 μg/mL +/− + 1141022″Rifaximin 2 10 μg/mL +/− + 1141022 2  3 μg/mL +/− − 2  1 μg/mL +/− − 20.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− − 621500 25-Anaerobes in vitro 2 100 μg/mL  +/− − Helicobacter desacetyl 2 30 μg/mL+/− − pylori rifaximin 2 10 μg/mL +/− − (ATCC 43504) 2  3 μg/mL +/− − 2 1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − in vitro 2 0.03μg/mL  +/− − ″Rifaximin Anaerobes 2 100 μg/mL  +/− + ″ 2 30 μg/mL +/− +″ 2 10 μg/mL +/− + ″ 2  3 μg/mL +/− + 2  1 μg/mL +/− − 2 0.3 μg/mL  +/−− 2 0.1 μg/mL  +/− − in vitro 2 0.03 μg/mL  +/− − 614000 25- GramNegative in vitro 2 100 μg/mL  +/− − Pseudomonas desacetyl 2 30 μg/mL+/− − aeruginosa rifaximin 2 10 μg/mL +/− − (ATCC 9027) 2  3 μg/mL +/− −2  1 μg/mL +/− − 2 0.3 μg/mL  +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/−− ″Rifaximin Gram Negative in vitro 2 100 μg/mL  +/− + ″ 2 30 μg/mL+/− + ″ 2 10 μg/mL +/− + 2  3 μg/mL +/− − 2  1 μg/mL +/− − 2 0.3 μg/mL +/− − 2 0.1 μg/mL  +/− − 2 0.03 μg/mL  +/− −

620000 Bacteroides fragilis (ATCC 23745) Culture Medium: ReinforcedClostridial Medium Vehicle: 1% DMSO Incubation Time/Temp: 2 days at 37°C. Incubation Volume: 1 mL Time of Assessment: 2 days QuantitationMethod: Turbidity Measurement

620600 Clostridium defficile (ATCC 9689) Culture Medium: ReinforcedClostridial Medium Vehicle: 1% DMSO Incubation Time/Temp: 2 days at 37°C. Incubation Volume: 3 mL Time of Assessment: 2 days QuantitationMethod: Turbidity Measurement

620700 Clostridium perfringens (ATCC 13124) Culture Medium: ReinforcedClostridial Medium Vehicle: 1% DMSO Incubation Time/Temp: 2 days at 37°C. Incubation Volume: 3 mL Time of Assessment: 2 days QuantitationMethod: Turbidity Measurement

620500 Clostridium sporogenes (ATCC 7955) Culture Medium: ReinforcedClostridial Medium Vehicle: 1% DMSO Incubation Time/Temp: 2 days at 37°C. Incubation Volume: 3 mL Time of Assessment: 2 days QuantitationMethod: Turbidity Measurement

611500 Enterobacter cloacae (ATCC 13047) Culture Medium: Mueller-HintonBroth Vehicle: 1% DMSO Incubation Time/Temp: 20 hours at 37° C.Incubation Volume: 1 mL Time of Assessment: 1 day Quantitation Method:Turbidity Measurement

602100 Enterococcus faecalis (VRE, ATCC 51575) Culture Medium: TrypticSoy Broth with 7% FBS Vehicle: 1% DMSO Incubation Time/Temp: 20 hours at37° C. Incubation Volume: 1 mL Time of Assessment: 1 day QuantitationMethod: Turbidity Measurement

610000 Escherichia coli (ATCC 10536) Culture Medium: Mueller-HintonBroth Vehicle: 1% DMSO Incubation Time/Temp: 20 hours at 37° C.Incubation Volume: 1 mL Time of Assessment: 1 day Quantitation Method:Turbidity Measurement

610100 Escherichia coli (ATCC 25922) Culture Medium: Mueller-HintonBroth Vehicle: 1% DMSO Incubation Time/Temp: 20 hours at 37° C.Incubation Volume: 1 mL Time of Assessment: 1 day Quantitation Method:Turbidity Measurement

611000 Escherichia coli (Juhl) Culture Medium: Mueller-Hinton BrothVehicle: 1% DMSO Incubation Time/Temp: 20 hours at 37° C. IncubationVolume: 1 mL Time of Assessment: 1 day Quantitation Method: TurbidityMeasurement

621500 Helicobacter pylori (ATCC 43504) Culture Medium: Columbia AgarBase + 7% defibrinated rabbit blood Vehicle: 1% DMSO IncubationTime/Temp: 2 days at 37° C. Incubation Volume: 1 mL Time of Assessment:4 days Quantitation Method: Inhibition of colony growth was read

614000 Pseudomonas aeruginosa (ATCC 9027) Culture Medium: Mueller-HintonBroth Vehicle: 1% DMSO Incubation Time/Temp: 20 hours at 37° C.Incubation Volume: 1 mL Time of Assessment: 1 day Quantitation Method:Turbidity Measurement

In Vitro Activity of Rifaximin and 25-Desacetyl Rifaximin

The in vitro activities of rifaximin and 25-desacetyl rifaximin areshown in the tables below (e.g., Tables 2, 3, and 4) as a range ofMinimum Inhibitory Concentration (MIC) values encountered and MIC₅₀ andMIC₉₀.

TABLE 2a Activity against Enterobacteriaceae spp. strains Range MIC₅₀MIC₉₀ Mode Antimicrobial Agent (mg/L) (mg/L) (mg/L) (mg/L) Rifaximin 8-32 32 32 32 25-Desacetyl rifaximin 128-256 128 256 128

TABLE 2b Activity against Enterobacteriaceae spp. strains MIC (mg/L)25-Desacetyl N. Strains Rifaximin rifaximin 1 ATCC E. coli 25922 16 1282 C. freundii 57 16 128 3 C. freundii 58 32 128 4 C. freundii 65 32 1285 C. freundii 68 32 256 6 C. freundii 69 32 128 7 C. freundii 1070 32128 8 C. freundii 1073 32 256 9 C. freundii 1075 32 128 10 E. aerogenes235 32 128 11 E. aerogenes 281 32 128 12 E. aerogenes 290 32 128 13 E.aerogenes 1023 32 128 14 E. aerogenes 1030 32 256 15 E. aerogenes 103132 128 16 E. cloacae 3 32 128 17 E. cloacae 7 32 128 18 E. cloacae 8 32256 19 E. cloacae 12 32 128 20 E. cloacae 13 32 128 21 E. cloacae 14 32128 22 E. cloacae 16 32 128 23 E. cloacae 20 32 128 24 E. cloacae 321 32128 25 E. cloacae 348 32 256 26 E. cloacae 349 32 128 27 E. cloacae 35832 128 28 E. cloacae 367 32 128 29 E. cloacae 369 32 256 30 E. sacazakii9 32 128 31 E. sacazakii 11 32 128 32 E. coli 104 32 128 33 E. coli 6 32128 34 E. coli 15 16 128 35 E. coli 34 32 128 36 E. coli 37 8 128 37 E.coli 41 16 128 38 E. coli 43 16 128 39 E. coli 44 16 256 40 E. coli 4616 128 41 E. coli 47 32 128 42 E. coli 48 32 256 43 E. coli 49 32 128 44E. coli 56 32 128 45 E. coli 62 32 128 46 E. coli 71 8 128 47 E. coli 9016 128 48 E. coli 92 32 128 49 E. coli 93 32 256 50 E. coli 95 32 128 51E. coli 96 8 128 52 E. coli 97 32 128 53 E. coli 100 32 128 54 E. coli102 16 128 55 E. coli 103 32 128 56 E. coli 109 32 128 57 E. coli 110 32256 58 E. coli 112 32 128 59 E. coli 113 32 128 60 E. coli 117 16 256 61E. coli 118 32 128 62 E. coli 120 32 128 63 E. coli 140 32 256 64 E.coli 171 32 128 65 E. coli 342 32 128 66 E. coli 343 32 256 67 E. coli345 32 128 68 E. coli 349 32 128 69 E. coli 351 32 128 70 K. pneumoniae17 32 128 71 K. pneumoniae 19 32 128 72 K. pneumoniae 76 32 256 73 K.pneumoniae 80 32 128 74 K. pneumoniae 91 32 128 75 K. pneumoniae 1064 32128 76 K. oxytoca 4 32 128 77 K. oxytoca 18 32 128 78 K. oxytoca 479 32128 79 K. oxytoca 499 32 128 80 M. morganii 42 16 128 81 M. morganii 4832 128 82 M. morganii 50 32 128 83 M. morganii 57 32 256 84 M. morganii67 32 256 85 M. morganii 101 32 128 86 M. morganii 105 32 128 87 M.morganii 108 32 128 88 M. morganii 453 8 128 89 M. morganii 458 32 25690 M. morganii 461 32 128 91 M. morganii 462 32 128 92 M. morganii 92316 128 93 M. morganii 932 32 128 94 M. morganii 935 32 256 95 M.morganii 1006 8 128 96 P. mirabilis 465 32 128 97 P. mirabilis 466 32128 98 P. mirabilis 469 32 128 99 P. mirabilis 470 16 128 100 P.mirabilis 471 8 256 101 P. mirabilis 472 8 128 102 P. mirabilis 473 16128 103 P. mirabilis 477 32 128 104 P. mirabilis 479 32 128 105 P.mirabilis 480 32 256 106 P. mirabilis 489 32 128 107 P. mirabilis 928 32128 108 P. mirabilis 972 32 128 109 P. mirabilis 983 16 128 110 P.mirabilis 985 32 256 111 P. mirabilis 987 32 128 112 P. mirabilis 988 8128 113 P. mirabilis 990 32 128 114 P. mirabilis 991 32 128 115 P.mirabilis 993 16 128 116 P. mirabilis 995 32 128 117 P. mirabilis 996 32128 118 P. mirabilis 997 32 128 119 P. mirabilis 998 8 256 120 P.stuartii 94 32 128 121 P. stuartii 299 16 128 122 P. stuartii 301 32 128123 P. stuartii 306 16 256 124 P. stuartii 312 32 128 125 P. stuartii459 32 128 126 S. liquefaciens 53 32 128 127 S. liquefaciens 55 32 256128 S. marcescens 38 32 128 129 S. marcescens 45 32 128 130 S.marcescens 59 32 128 131 S. marcescens 63 32 256 132 S. odorifera 52 32128 133 S. odorifera 59 32 128 134 S. maltophilia 1203 32 128 135 S.maltophilia 1208 32 128

TABLE 3a Activity against Staphylococcus spp. strains Range MIC₅₀ MIC₉₀Mode Antimicrobial Agent (mg/L) (mg/L) (mg/L) (mg/L) Rifaximin 0.03-1 0.25 1 0.5 25-Desacetyl rifaximin 0.12->16 2 16 2

TABLE 3b Activity against Staphylococcus spp. strains MIC (mg/L)25-Desacetyl N. Strains Rifaximin rifaximin 1 ATCC S. aureus 29213 0.0150.5 2 S. aureus 215 1 16 3 S. aureus 234 0.25 2 4 S. aureus 236 1 16 5S. aureus 237 0.06 2 6 S. aureus 238 0.03 0.25 7 S. aureus 246 0.5 2 8S. aureus 252 0.5 4 9 S. aureus 253 0.12 1 10 S. aureus 267 1 16 11 S.aureus 272 0.25 2 12 S. aureus 279 0.03 0.25 13 S. aureus 327 1 4 14 S.aureus 328 0.5 2 15 S. aureus 329 1 4 16 S. aureus 339 1 16 17 S. aureus345 0.25 2 18 S. aureus 355 0.5 2 19 S. aureus 406 0.5 >16 20 S. aureus408 0.25 2 21 S. aureus 409 0.12 1 22 S. aureus 416 0.5 2 23 S. aureus425 0.5 >16 24 S. aureus 436 0.06 2 25 S. aureus 475 0.5 4 26 S.epidermidis 332 0.06 0.12 27 S. epidermidis 354 0.06 0.12 28 S.haemolyticus 243 0.06 0.5 29 S. haemolyticus 276 0.12 1 30 S.haemolyticus 955 0.12 1 31 S. haemolyticus 982 0.06 0.5 32 S. xylosus337 0.5 2 33 S. xylosus 346 0.5 2 34 S. spp. 1102 0.06 1 35 S. spp. 11870.03 2 36 S. spp. 1195 0.06 0.12 37 S. spp. 1256 0.12 4 38 S. spp. 13120.25 4 39 S. spp. 1689 1 4 40 S. spp. 1745 0.06 0.25

TABLE 4a Activity against Enterococcus spp. strains Range MIC₅₀ MIC₉₀Mode Antimicrobial Agent (mg/L) (mg/L) (mg/L) (mg/L) Rifaximin 2->168 >16 4 25-Desacetyl rifaximin 4->16 >16 >16 >16

TABLE 4b Activity against Enterococcus spp. strains MIC (mg/L)25-Desacetyl N. Strains Rifaximin rifaximin 1 ATCC E. faecalis 29212 416 2 E. faecalis 181 4 >16 3 E. faecalis186 4 4 4 E. faecalis 187 4 4 5E. faecalis 193 4 4 6 E. faecalis 194 4 >16 7 E. faecalis 200 >16 >16 8E. faecalis 204 4 4 9 E. faecalis 205 4 >16 10 E. faecalis 210 4 4 11 E.faecalis 227 >16 >16 12 E. faecalis 228 4 4 13 E. faecalis 232 4 4 14 E.faecalis 235 16 >16 15 E. faecalis 237 4 4 16 E. faecalis 239 8 >16 17E. faecalis 242 >16 >16 18 E. faecalis 243 16 >16 19 E. faecalis245 >16 >16 20 E. faecalis 249 4 4 21 E. faecalis 250 4 >16 22 E.faecalis 251 8 >16 23 E. faecalis 255 4 4 24 E. faecium 8 4 4 25 E.faecium 13 4 4 26 E. faecium 174 8 >16 27 E. faecium 185 >16 >16 28 E.faecium 188 8 >16 29 E. faecium 189 4 8 30 E. faecium 190 16 >16 31 E.faecium 191 >16 >16 32 E. faecium 192 2 8 33 E. faecium 198 16 >16 34 E.faecium 199 8 >16 35 E. faecium 201 16 >16 36 E. faecium 203 4 8 37 E.faecium 207 4 >16 38 E. faecium 208 2 4 39 E. faecium 209 16 >16 40 E.faecium 212 >16 >16 41 E. faecium 215 >16 >16 42 E. faecium 217 8 4 43E. faecium 221 8 >16 44 E. faecium 222 >16 >16 45 E. faecium 223 >16 >1646 E. faecium 225 4 >16 47 E. faecium 229 2 8 48 E. faecium 230 8 4 49E. faecium 231 16 >16 50 E. faecium 236 2 4 51 E. faecium 238 16 >16 52E. faecium 240 >16 >16 53 E. faecium 248 >16 >16

Radioligand Binding Assays—the Activity of 25-Desacetyl Rifaximin

Methods employed in this study have been adapted from the scientificliterature to maximize reliability and reproducibility. Referencestandards were run as an integral part of each assay to ensure thevalidity of the results obtained. Assays were performed under conditionsdescribed in the accompanying “Methods” section below. The literaturereference(s) for each assay are in the “Literature References” section.

Where presented, IC₅₀ values were determined by a non-linear, leastsquares regression analysis using MathIQ™ (ID Business Solutions Ltd.,UK). Where inhibition constants (K_(I)) are presented, the K_(I) valueswere calculated using the equation of Cheng and Prusoff (Cheng, Y.,Prusoff, W. H., Biochem. Pharmacol. 22:3099-3108, 1973) using theobserved IC₅₀ of the tested compound, the concentration of radioligandemployed in the assay, and the historical values for the K_(D) of theligand (obtained experimentally at Ricerca Biosciences, LLC). Wherepresented, the Hill coefficient (n_(H)), defining the slope of thecompetitive binding curve, was calculated using MathIQ™. Hillcoefficients significantly different than 1.0 may suggest that thebinding displacement does not follow the laws of mass action with asingle binding site. Where IC₅₀, K_(I), and/or n_(H) data are presentedwithout Standard Error of the Mean (SEM), data are insufficient to bequantitative, and the values presented (K_(I), IC₅₀, n_(H)) should beinterpreted with caution.

Significant results are displayed in the following table(s) in rankorder of potency for estimated IC₅₀ and/or K_(I) values.

Biochemical assay results are presented as the percent inhibition ofspecific binding or activity throughout the report. All other resultsare expressed in terms of that assay's quantitation method (see Methodssection). For primary assays, only the lowest concentration with asignificant response judged by the assays' criteria, is shown in thissummary.

Where applicable, either the secondary assay results with the lowestdose/concentration meeting the significance criteria or, if inactive,the highest dose/concentration that did not meet the significancecriteria is shown.

Unless otherwise requested, primary screening in duplicate withquantitative data (e.g., IC50±SEM, Ki±SEM and nH) are shown whereapplicable for individual requested assays. In screening packages,primary screening in duplicate with semi-quantitative data (e.g.,estimated IC50, Ki and nH) are shown where applicable (concentrationrange of 4 log units); available secondary functional assays are carriedout (30 mM) and MEC or MIC determined only if active in primaryassays >50% at 1 log unit below initial test concentration. Significantresponses (50% inhibition or stimulation for Biochemical assays) werenoted in the primary assays listed below:

PRIMARY BIOCHEMICALASSAY SPECIES CONC. % INH. Bombesin BB1 hum 10 μM 53N-Formyl Peptide Receptor FPR1 hum 10 μM 54

As shown above, each of rifaximin and 25-desacetyl rifaximin werescreened at 10 μM against 168 targets; a screen was consideredsignificant if a 50% effect (either inhibition or stimulation) wasobserved. For 25-desacetyl, there were two “hits”: Bombesin BB1 andN-formyl peptide receptor FPR1—each achieved just over 50% inhibition.No hits were reported for rifaximin (although potency against bombesinand FPR1 appear to be just below the 50% threshold).

Accordingly, provided herein are method of inhibiting Bombesin BB1 byadministering 25-desacetyl rifaximin. Also provided herein are methodsof inhibiting N-formyl peptide receptor FPR1 by administering25-desacetyl rifaximin.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments described herein. Such equivalents are intended to beencompassed by the following claims.

All references cited herein, whether in print, electronic, computerreadable storage media or other form, are expressly incorporated byreference in their entirety and may be employed in the practice of theinvention, including for example, abstracts, articles, journals,publications, texts, treatises, technical data sheets, manufacturer'sinstructions, descriptions, product specifications, product sheets,internet web sites, databases, patents, patent applications, and patentpublications.

We claim:
 1. A sodium, potassium, calcium, magnesium, ammonium, orchlorine pharmaceutically acceptable salt of 25-desacetyl rifaximin,wherein the 25-desacetyl rifaximin is of the formula:


2. A pharmaceutically acceptable acid addition salt of 25-desacetylrifaximin, wherein the 25-desacetyl rifaximin is of the formula:


3. The pharmaceutically acceptable acid addition salt of claim 2,wherein the acid addition salt is selected from hydrochloric, nitric,phosphoric, sulfuric, hydrobromic, hydriodic, hydrofluoric, phosphorous,sulfate, pyrosulfate, bisulfate, sulfite, bisulfite, nitrate, phosphate,monohydrogenphosphate, dihydrogenphosphate, metaphosphate,pyrophosphate, acetate, trifluoroacetate, propionate, caprylate,isobutyrate, oxalate, malonate, succinates suberate, sebacate, fumarate,maleate, mandelate, benzoate, chlorobenzoate, methylbenzoate,dinitrobenzoate, phthalate, benzensoulfonate, toluenesulfonate,phenylacetate, citrate, lactate, maleate, tartrate, andmethanesulfonate.
 4. A pharmaceutically acceptable base addition salt of25-desacetyl rifaximin, wherein the 25-desacetyl rifaximin is of theformula:


5. The pharmaceutically acceptable acid addition salt of claim 4,wherein the base addition salt is selected from sodium, potassium,magnesium, and calcium.
 6. A pharmaceutical composition comprising thepharmaceutically acceptable salt of 25-desacetyl rifaximin according toclaim 1; and a pharmaceutically acceptable carrier.
 7. A pharmaceuticalcomposition comprising the pharmaceutically acceptable salt of25-desacetyl rifaximin according to claim 2; and a pharmaceuticallyacceptable carrier.
 8. A pharmaceutical composition comprising thepharmaceutically acceptable 25-desacetyl rifaximin according to claim 4;and a pharmaceutically acceptable carrier.
 9. A method for treatingirritable bowel syndrome, travelers' diarrhea, small intestinalbacterial overgrowth, or hepatic encephalopathy, comprisingadministering to a subject in need thereof a therapeutically effectiveamount of the pharmaceutically acceptable salt of 25-desacetyl rifaximinaccording to claim
 1. 10. The method of claim 9, wherein the traveler'sdiarrhea is caused by exposure to one or more enteric pathogens.
 11. Themethod of claim 10, wherein the one or more enteric pathogens isselected from Salmonella spp., Shigella spp., Campylobacter spp.,Aeromonas, Plesiomonas, Vibro spp., Yersinia entercolitica, E. coli,Enterotoxigenic Escherichia coli (ETEC), E. coli 0157:H7, C. difficileand H. pylori.
 12. The method of claim 10, wherein the enteric pathogenscomprise one or more of a gram-positive bacteria, a gram-negativebacteria, an aerobic bacteria or an anaerobic bacteria.
 13. A method fortreating irritable bowel syndrome, travelers' diarrhea, small intestinalbacterial overgrowth, or hepatic encephalopathy, comprisingadministering to a subject in need thereof a therapeutically effectiveamount of the pharmaceutically acceptable salt of 25-desacetyl rifaximinaccording to claim
 2. 14. The method of claim 13, wherein the traveler'sdiarrhea is caused by exposure to one or more enteric pathogens.
 15. Themethod of claim 14, wherein the one or more enteric pathogens isselected from Salmonella spp., Shigella spp., Campylobacter spp.,Aeromonas, Plesiomonas, Vibro spp., Yersinia entercolitica, E. coli,Enterotoxigenic Escherichia coli (ETEC), E. coli 0157:H7, C. difficileand H. pylori.
 16. The method of claim 14, wherein the enteric pathogenscomprise one or more of a gram-positive bacteria, a gram-negativebacteria, an aerobic bacteria or an anaerobic bacteria.
 17. A method fortreating irritable bowel syndrome, travelers' diarrhea, small intestinalbacterial overgrowth, or hepatic encephalopathy, comprisingadministering to a subject in need thereof a therapeutically effectiveamount of the pharmaceutically acceptable salt of 25-desacetyl rifaximinaccording to claim
 4. 18. The method of claim 17, wherein the traveler'sdiarrhea is caused by exposure to one or more enteric pathogens.
 19. Themethod of claim 18, wherein the one or more enteric pathogens isselected from Salmonella spp., Shigella spp., Campylobacter spp.,Aeromonas, Plesiomonas, Vibro spp., Yersinia entercolitica, E. coli,Enterotoxigenic Escherichia coli (ETEC), E. coli 0157:H7, C. difficileand H. pylori.
 20. The method of claim 18, wherein the enteric pathogenscomprise one or more of a gram-positive bacteria, a gram-negativebacteria, an aerobic bacteria or an anaerobic bacteria.